The present invention relates generally to heat curable composite textile fabrics that may be cured to form a more rigid, non-flammable, heat resistant and insulating fabric. More specifically, the present invention includes a heat curable, circular or warp knitted fabric containing reinforcing and meltable resin fibers that can be cured to produce a more rigid material form. This composite textile may be used in any application that requires a rigid, heat resistant, non-flammable insulation or sleeve positioned around machine components having a specific shape. Application examples include exhaust insulation covers, pipe insulation covers, machinery covers (such as covers for turbines), rigid fire barrier panels, gun barrel covers, engine component covers, and the like.
Traditional composite structures are typically woven or axial fabric with longitudinal fibers to maximize composite strength and rigidity, but typically require a liquid resin and some form of molding, usually compression molding or vacuum molding, which are time consuming and expensive manufacturing processes that require complex equipment.
Compression molding is a forming process in which a plastic material is placed directly into a heated metal mold, then is softened by the heat, and forced to conform to the shape of the mold as the mold closes. The compression molding starts, with an allotted amount of plastic or gelatin placed over or inserted into a mold. Afterward the material is heated to a pliable state in and by the mold. Shortly there after the hydraulic press compresses the pliable plastic against the mold, resulting in a perfectly molded piece, retaining the shape of the inside surface of the mold. After the hydraulic press releases, an ejector pin in the bottom of the mold quickly ejects the finish piece out of the mold and then the process is finished. Compression molding is a high-volume, high-pressure method suitable for molding complex, high-strength fiberglass reinforcements. Advanced composite thermoplastics can also be compression molded with unidirectional tapes, woven fabrics, randomly oriented fiber mat or chopped strand. The advantage of compression molding is its ability to mold large, fairly intricate parts. However, compression molding often provides poor product consistency and difficulty in controlling flashing, and it is not suitable for some types of parts. Fewer fiber lines are produced and a smaller amount of fiber-length degradation is noticeable when compared to injection molding. Compression-molding is also suitable for ultra-large basic shape production in sizes beyond the capacity of extrusion techniques. Materials that are typically manufactured through compression molding include: Polyester fiberglass resin systems (SMC/BMC), Torlon, Vespel, Poly(p-phenylene sulfide) (PPS), and many grades of PEEK.
Vacuum molding or forming is a simplified version of thermoforming, whereby a sheet of plastic is heated to a forming temperature, stretched onto or into a single-surface mold, and held against the mold by applying a vacuum between the mold surface and the sheet. The vacuum forming process can be used to make most product packaging, speaker casings, and even car dashboards. Vacuum forming is usually, but not always, restricted to forming plastic parts that are rather shallow in depth. A thin sheet is formed into rigid cavities for unit doses of pharmaceuticals and for loose objects that are carded or presented as point-of-purchase items. Thick sheet is formed into permanent objects such as turnpike signs and protective covers. Relatively deep parts can be formed if the form-able sheet is mechanically or pneumatically stretched prior to bringing it in contact with the mold surface and before vacuum is applied. Suitable materials for use in vacuum forming are conventionally thermoplastics. The most common and easiest to use thermoplastic is High Impact Polystyrene Sheeting (HIPS). This is molded around a wood, structural foam or cast/machined aluminum mold and can form to almost any shape.
Each of these methods has disadvantages, including expensive equipment and time-consuming processes. Thus, there is a need for a composite textile material that may be cured and formed into any desired shape, wherein the final material becomes more rigid, tough, and is resistant to heat. Further, there is a need for a more cost-effective, less time-consuming process for manufacturing such a product. It would be desirable to provide a product and method for applying a protective cover or wrap to mechanical components of various shapes and sizes, without having to produce individual molds for each specific cover.
For example, a company may produce thousands of different components of varying shapes and sizes, many of which require a cover or wrap for purposes of insulation and protection against heat and corrosion. In order to provide such covers or wraps for these various components using compression molding or vacuum molding, it would be necessary to provide a mold for each section of covering to be applied to the thousands of corresponding components to be wrapped or covered. Thus, the present invention is directed to a product and process that may be used to apply these wraps or covers to components of any size and shape, without the necessity of providing individual molds for each different size or shape.